摘要
结合汶川地震灾区公路隧道震害资料,文章制定了公路隧道震害量化指标并进行分级,对汶川地震公路隧道震害规律进行了研究.研究结果表明:隧道衬砌开裂长度占隧道总长度比例最高,二次衬砌垮塌及仰拱错台长度次之;多数震害类型在Ⅴ级围岩中发生的比例均高于其它级别围岩;Ⅹ、Ⅺ度地震烈度区,断层段破坏程度最严重,其次是洞口段;震害严重程度随震中距增加而迅速衰减,发生严重以上震害的隧道集中于10 km以内,近三分之二发生于20 km范围;坚硬岩体中的隧道,震害程度随埋深增加而减轻,软弱围岩中的隧道,震害程度与埋深关系不明确;发生严重以上震害的隧道,实际地震烈度均高于设防烈度,出现中等震害的隧道,近三分之二的隧道实际地震烈度高于设防烈度;隧道轴线与发震断层交角为60°~90°,震害严重,轴线与发震断层交角为30°~60°,震害相对较轻;防水板致使初期支护和二次衬砌在地震时不能协同工作,增加震害风险.
Abstract
Quantitative indicators and a classification system of seismic damages to highway tunnels were developed based on a study of the seismic damage rules for highway tunnels in the Wenchuan seismic area. The results show that:the proportion of tunnel lining crack length is the highest along the total length of tunnel, and the length of sec-ondary lining collapse and inverted arch dislocation goes the second;the proportion of most types of damage in sur-rounding rock of grade Ⅴ is higher than that in surrounding rocks of other grades;in the area with Ⅹ&Ⅺ seismic intensities, damage at the fault section is the worst, and the damage at the portal section comes the second;the seis-mic damage severity decays quickly with increased distance from the epicenter, and the tunnels most seriously dam-aged are mostly located less than 10 km away from the epicenter, and nearly two-thirds of them are within 20 km;the degree of seismic damage to the tunnel in hard rock decreases with an increase of buried depth, and the relation-ship between the degree of damage and buried depth is unclear regarding tunnels in soft rock;the actual seismic in-tensities are higher than the fortification intensities specified for the tunnels with serious damage, and as for tunnels with moderate damage, nearly two-thirds of them have higher seismic intensities than the designed ones; seismic damage is serious when the crossing angle between the tunnel axis and the seismogenic fault is 60°~90° , and it is relatively light under angles of 30°~60°;and the primary support and secondary lining can′t work cooperatively dur-ing an earthquake because of the waterproof membrane, which increases the risk of seismic damage.
基金项目
福建省自然科学基金(2016J01205)
福建省自然科学基金(2014J01170)
中铁二十四局集团福建铁路建设有限公司科研项目(GY-H-15034)
NETL
NSTL
维普
万方数据